1. Field of the Invention
The present invention relates to a safety scanner, an optical safety system, and a setting support device for a safety scanner, and, more particularly, to an improvement of an optical safety system that receives reflected light from an object to sense an intruder within a protection area.
2. Description of Related Art
An area monitoring sensor is a safety device which senses an intruder such as a person intruded into a protection area and outputs a safety control signal for emergently stopping a machine tool or an industrial robot (e.g., JP 2009-296087 A and JP 2009-294734 A).
For example, a safety scanner is an optical area monitoring sensor provided with a light emitting part which emits detection light toward an object, a light receiving part which receives reflected light from the object and generates a light receiving signal, a distance calculation part which obtains a distance to the object on the basis of the light receiving signal, and a scanning part which causes the detection light to perform scanning in the circumferential direction around a rotation axis. Sensing of an intruder is performed by identifying the position of an object from the distance to the object and a scanning angle of the detection light and checking the identified position against a protection area.
In a conventional safety scanner as described above, a position and a sensing time of a sensed intruder are recorded as a sensing history. It is possible to identify when and where the intruder has been sensed by analyzing the sensing history. However, disadvantageously, a state around the intruder cannot be grasped from such a sensing history. In particular, disadvantageously, a state before the time of sensing of the intruder and a state after the sensing time are uncertain, and it is difficult to identify what kind of intruder has intruded into the protection area and how the intruder has intruded into the protection area, or identify whether or not the intruder sensing is temporary sensing. Further, it is difficult to perform an analysis of a sensing factor such as whether or not the intruder sensing is caused by a positional deviation at the time of installation of the safety scanner or caused by setting error of the protection area.
For example, when the safety scanner is provided with a camera which captures an image of the protection area, a terminal device such as a personal computer may be connected to the safety scanner, and an image captured by the camera may be recorded by the terminal device. In the terminal device, an image at the time of sensing an intruder can be monitored. However, in a configuration that constantly records an image captured by the camera, it is extremely troublesome to find an image at the time of sensing an intruder from a huge amount of recorded data.